Question

我的表：

tbl_questions =>
qid
question
detail
mcid
cid
uid
answercount
dateposted
status
showname
emailnotify
question_type_id

我想按小时分组所有行。 {dateposted = Y-m-d H：i：s}我想将{question_type_id更新为2}，那时我的行数更多。

好吧，如果有人每小时得到15个问题我想给他们2型，但只有那个小时的那些消息（行）。对不起，很难说出我到底想要什么，我的英语很差。

sample data tbl_questions =＆gt;

qid = 1, uid = 1, dateposted = 2013-01-01 10:11:10, question_type_id = 1
qid = 2, uid = 1, dateposted = 2013-01-01 10:16:10, question_type_id = 1
qid = 3, uid = 1, dateposted = 2013-01-01 10:18:10, question_type_id = 1
qid = 4, uid = 1, dateposted = 2013-01-01 10:19:10, question_type_id = 1
qid = 5, uid = 1, dateposted = 2013-01-01 10:20:10, question_type_id = 1
qid = 6, uid = 1, dateposted = 2013-01-01 10:22:10, question_type_id = 1
qid = 7, uid = 1, dateposted = 2013-01-01 10:23:10, question_type_id = 1
qid = 8, uid = 1, dateposted = 2013-01-01 10:24:10, question_type_id = 1
qid = 9, uid = 1, dateposted = 2013-01-01 10:25:10, question_type_id = 1
qid = 10, uid = 1, dateposted = 2013-01-01 10:26:10, question_type_id = 1
qid = 11, uid = 1, dateposted = 2013-01-01 10:27:10, question_type_id = 1
qid = 12, uid = 2, dateposted = 2013-01-01 10:17:10, question_type_id = 1
qid = 13, uid = 2, dateposted = 2013-01-01 10:27:10, question_type_id = 1
qid = 14, uid = 1, dateposted = 2013-01-01 12:27:10, question_type_id = 1

我希望update rows posted by uid = 1他们set question_type_id = 2，Cos超过一小时限制。我需要在这些行中qid = 1, uid = 1, dateposted = 2013-01-01 10:11:10, question_type_id = 2 qid = 2, uid = 1, dateposted = 2013-01-01 10:16:10, question_type_id = 2 qid = 3, uid = 1, dateposted = 2013-01-01 10:18:10, question_type_id = 2 qid = 4, uid = 1, dateposted = 2013-01-01 10:19:10, question_type_id = 2 qid = 5, uid = 1, dateposted = 2013-01-01 10:20:10, question_type_id = 2 qid = 6, uid = 1, dateposted = 2013-01-01 10:22:10, question_type_id = 2 qid = 7, uid = 1, dateposted = 2013-01-01 10:23:10, question_type_id = 2 qid = 8, uid = 1, dateposted = 2013-01-01 10:24:10, question_type_id = 2 qid = 9, uid = 1, dateposted = 2013-01-01 10:25:10, question_type_id = 2 qid = 10, uid = 1, dateposted = 2013-01-01 10:26:10, question_type_id = 2 qid = 11, uid = 1, dateposted = 2013-01-01 10:27:10, question_type_id = 2 qid = 12, uid = 2, dateposted = 2013-01-01 10:17:10, question_type_id = 1 qid = 13, uid = 2, dateposted = 2013-01-01 10:27:10, question_type_id = 1 qid = 14, uid = 1, dateposted = 2013-01-01 12:27:10, question_type_id = 1。

所以预期的输出是： tbl_questions =＆gt;

{{1}}

Answer 1

您必须完成几个步骤。

假设您使用MySQL，请检查date & time functions。功能 HOUR（）可能是您想要的：

SELECT count(id) AS cpt, HOUR(dateposted) AS hour FROM tbl_questions GROUP BY hour ORDER BY cpt DESC;

从这里你可以提取最大数量和相关的小时数（至少一个，可能是几个，然后检索你表中的相关行。你可以构建一个所需小时数组并查询类似

UPDATE tbl_questions SET question_type_id = 2 WHERE HOUR(dateposted) IN (...your list of hours)

如何按小时对sql行进行分组？

1 个答案: